Review of PM generator designs for direct-drive wind turbines

A review of the direct drive permanent magnet generator technologies for wind energy is carried out in the paper. A preliminary study of the V-shaped interior permanent magnet (IPM) machine for application as the direct drive wind-power generator was also conducted. The air-gap flux density of this type of IPM machine has been studied which shows that by optimizing V angle, high air-gap flux density can be maintained even with small pole pitch angle of high pole number structure.